The present invention relates to a method for making beam leads for interconnecting electronic packages on a substrate and also for interconnecting adjacent substrates.
The above-referenced patent application describes a method for making beam leads wherein a copper foil pattern is first etched, and then a second metal having poor adhesion with said copper foil is deposited onto the metal foil. The second metal is then separated from the copper foil and the foil is reusable as a depository for another deposition of the second metal which is the desired beam leads. The individual beam leads are preferably attached to the substrate or electronic assembly by an ultrasonic bonding technique. When the beam leads are used in a nonplanar configuration, a bending fixture is preferably used to shape the aluminum leads in order to prevent cracking and bending at the ultrasonic bond interface.